Recently, a variety of services and additional new features provided by electronic devices has rapidly increased. In order to enhance the enjoyment of electronic devices, service providers and device manufacturers are competitively developing useful functions to meet various demands of users so as to differentiate from their competitors.
Today, electronic devices being incorporated into a wearable device that is worn on the body. The electronic devices that can be worn on bodies may include, for example, a head-mounted electronic device, such as a Head-Mounted Display (HMD).
A head-mounted display device may be worn on a user's body part (for example, the user's head) to simulate a virtual-reality environment or an augmented-reality environment to the user. To this end, a display screen is provided with user interfaces to enable computer-generated environment that let you experience a different reality.